rhysiologcial Studies ou ScListostega osmund^iuea. 25 



2) Calcium sulphate. — In 0.2 and 0.3% solutions, the moss 

 did not produce a single adventive protonema in 2 weeks. After 

 2 months had passed, it was observed to have produced a few 

 protonemata, but no lateral innovations whatever. In 0.05 and 

 O.lX solutions, it produced a few adventive protonemata in 2 

 weeks and a few lateral innovations in 2 months. 



3) Calcium chloride. — In a 0.05^ solution, the moss pro- 

 duced a few adventive protonemata in two weeks, but then it 

 almost ceased to grow. In O.lX, 0.2X and 0.3% solutions, the 

 moss produced no adventive protonemata at all in 2 weeks, but 

 after 2 months, the moss in the 0.3% solution was seen to have 

 produced a few lateral innovations. In a 0.2^ solution the moss 

 produced more lateral innovations and in 0.1^ still more (Fig. 

 21). Thus 0.1^ of calcium nitrate, of calcium sulphate, and of 

 calcium chloride seem to stimulate the growth of the moss to tlie 

 highest degree. 



4) Calcium carbonate. — All the shoots put in 0.3, 0.2, 0.1 

 and O.OS^" solutions produced a few adventive protonemata in two 

 weeks. The moss grew best in the O.lX solution. After 3 weeks, 

 the shoots in 0.05 and 0.1/6^ solutions were seen to have produced 

 a large number of adventive protonemata. The shoots in 0.2 and 

 0.3% solutions produced only a few adventive protonemata, and did 

 not make any growth even after 5 weeks ; in 0.05 and 0.1% 

 solutions, they produced many adventive protonemata and a few 

 lateral innovations fi'om the stem floating on the surface of the 

 liquid. From these experiments I infer that in this case also 0.05 

 and 0.1% are the most suitable degrees of concentration. 



It seems probable that Schistostega does not dislike lime, at least 

 not in the above-mmtioned concentratiom. 



